To measure half of a large egg, beat the whole egg until the white and yolk are fully combined, then measure out 1.5 tablespoons — that’s 25 g, exactly half. Discard or refrigerate the other 25 g in an airtight container for up to 2 days.
This comes up whenever you’re halving a recipe that calls for 1 egg, or scaling to an odd number like 1.5 batches of a recipe that calls for 1 egg per batch.
Egg size and weight reference
A large egg is the standard size in most American baking recipes. King Arthur Baking’s weight chart gives:
| Part | Weight | Approx. tablespoons |
|---|---|---|
| Whole large egg (shell off) | 50 g | 3 tablespoons |
| Egg white only | 30–35 g | 2 tablespoons |
| Egg yolk only | 14–18 g | 1 tablespoon |
| Half a large egg | 25 g | 1.5 tablespoons |
| Third of a large egg | 17 g | 1 tablespoon |
| Quarter of a large egg | 12–13 g | 3/4 tablespoon |
Note: tablespoon values assume the egg is beaten and fully combined before measuring.
Step-by-step: halving one egg
- Crack one large egg into a small bowl.
- Beat with a fork until the white and yolk are fully combined and uniform in color.
- Measure 1.5 tablespoons (25 g) into your recipe.
- Store the remaining 1.5 tablespoons in a small covered container in the refrigerator. Use within 2 days in scrambled eggs, an omelet, or another recipe.
Fractional egg chart for common scaling factors
| Scale factor applied to 1 egg | Amount needed | Measure |
|---|---|---|
| 0.25 (quarter recipe) | 0.25 egg | 3/4 tbsp (12 g) |
| 0.33 (third recipe) | 0.33 egg | 1 tbsp (17 g) |
| 0.5 (half recipe) | 0.5 egg | 1.5 tbsp (25 g) |
| 0.67 (two-thirds) | 0.67 egg | 2 tbsp (33 g) |
| 0.75 (three-quarters) | 0.75 egg | 2.25 tbsp (37 g) |
| 1.5 (1.5x recipe) | 1.5 eggs | 1 egg + 1.5 tbsp |
| 2.5 (2.5x recipe from 1 egg) | 2.5 eggs | 2 eggs + 1.5 tbsp |
When it’s fine to round
Eggs provide protein (structure), fat (richness and tenderness), moisture, and emulsification. The effect of being slightly off depends on the recipe:
Round up (use a whole extra egg) when:
- The recipe is forgiving: muffins, quick breads, banana bread, cookies
- The scale factor is close to a whole number (e.g., 1.4 → use 1 egg, or 1.6 → use 2 eggs)
- You’d rather have the recipe turn out a little richer
Measure precisely when:
- The recipe is delicate: cheesecakes, soufflés, custards, choux pastry
- You’re already at a high multiple and small errors compound
- You’re baking professionally and consistency matters
What happens if you use too many eggs
Excess egg protein tightens the crumb — bread and cake become denser and slightly chewy. In custard-based recipes, too many eggs causes curdling. A single extra half-egg in a muffin recipe will not make a noticeable difference; a full extra egg in a custard might.
Using just the white or just the yolk
If your recipe calls for eggs primarily for leavening (many foam cakes), the white is more important — it forms the air-trapping protein network. If the recipe relies on eggs for richness and binding (pastry cream, hollandaise), the yolk is more important.
These distinctions rarely apply when simply halving a standard recipe. Beat the whole egg and measure 1.5 tablespoons unless you have a specific reason to separate.
Egg size equivalents across US grades
Most American baking recipes assume large eggs. If you have a different size, this affects how much beaten egg to use for a “half egg”:
| Egg size | Shell-off weight | Half egg |
|---|---|---|
| Small | ~38 g | ~19 g / 1.1 tbsp |
| Medium | ~44 g | ~22 g / 1.3 tbsp |
| Large | ~50 g | ~25 g / 1.5 tbsp |
| Extra-large | ~56 g | ~28 g / 1.7 tbsp |
| Jumbo | ~63 g | ~31.5 g / 1.9 tbsp |
Per USDA Egg Grading Manual standards. “Shell-off weight” is the edible portion — white plus yolk, no shell.
If a recipe calls for large eggs and you only have medium, substitute 1 medium per large for whole-egg recipes (the 12% weight difference rarely matters). For halved amounts, weigh — measuring tablespoons of beaten egg is more consistent than estimating by size.
UK and Australian egg sizing
UK and Australian eggs use a size grading by weight, not by name:
| UK/EU Grade | Weight range | US equivalent |
|---|---|---|
| Small (S) | Under 53 g | Medium |
| Medium (M) | 53–63 g | Large |
| Large (L) | 63–73 g | Extra-large |
| Extra-large (XL) | 73 g+ | Jumbo |
UK recipes calling for “2 medium eggs” use eggs in the 53–63 g range — roughly equivalent to US large eggs. When adapting a UK recipe using US large eggs, use the same count. When halving a UK recipe calling for 1 medium egg, beat the egg and measure 26–27 g (about 1.5 tablespoons of beaten egg, same as a US large half-egg).
What to do with the other half
Don’t discard the remaining half egg. It keeps well in a small, covered container in the refrigerator for up to 2 days. Uses include:
- Scrambled eggs
- French toast (add to the egg mixture)
- Egg wash for pastry (beat 1.5 tablespoons with 1 tablespoon water)
- Another baking recipe later in the day
If you find yourself repeatedly baking half-batches, consider switching to medium eggs rather than large — the smaller egg makes the math work out more often.
Storing partial eggs
- Beaten whole egg: Refrigerator up to 2 days, covered.
- Yolk only: Add a drop of water to prevent the surface from drying, cover, refrigerate up to 2 days.
- White only: Refrigerate up to 4 days, or freeze in an ice cube tray (1 white per cube) for up to 3 months.